The present invention relates to an inflatable air bag cushion for use in covering a side portion of a vehicle interior adjacent to an occupant to be protected during a collision event, and more particularly to an inflatable air bag cushion of substantially curtain-like structure for deployment away from the roof rail of the vehicle which air bag cushion includes an upwardly extending inflatable portion for deployment over the roof rail during a collision event.
It is well known in motor vehicles to provide air bag cushions for protecting a vehicle occupant wherein such air bag cushions are in fluid communication with gas generating inflators so as to inflate the cushions upon sensing predetermined vehicle conditions such as deceleration exceeding a certain level. It is further known to provide air bag systems including inflatable restraint cushions which are deployed from positions of attachment to the vehicle frame along the roof rail portion of the vehicle frame so as to extend downwardly in substantially curtain-like fashion between an occupant to be protected and the side portions of the vehicle adjacent to such occupant. Such coverage is intended to provide cushioning restraint for the occupant during a side impact or extended roll-over collision event. Such curtain-like structures thereby provide protection to the vehicle occupant in the regions below the roof rail of the vehicle. That is, the protection afforded by such downwardly deployed curtain-like structures extends substantially in the region below the zone of attachment along the roof rail.
In some instances such as during an extended roll-over event, it is contemplated that an occupant may come into contact with portions of the roof rail structure and the area above such structure. However, prior to the present invention, cushioning of these regions as well as the region below the roof rail is not believed to have been available using a single cushion construction.
This invention provides advantages and alternatives over the prior art by providing an air bag cushion which is deployed from a location along the roof rail portion of a vehicle frame in substantially curtain-like fashion across the sides of the vehicle interior over an expansive area adjacent to an occupant to be protected. The air bag cushion of the present invention further includes an inflatable region which expands upwardly towards the roof of the vehicle upon introduction of an inflating gas. Upon encountering resistance from the roof or other obstructive portion of the vehicle, the portion of the air bag cushion which expands upwardly away from the roof rail folds over at least a portion of the roof rail in a hinge-like manner thereby providing additional cushioning over the regions adjacent to the occupant to be protected. The curtain-like cushion of the present invention thus provides an extent of cushioning coverage which is not believed to have been provided by a single inflatable structure heretofore.
Preferably the air bag cushion of the present invention is attached to the roof rail portion of the vehicle frame along a line of attachment such that inflation is substantially restricted along the line of attachment thereby enhancing the ability of the inflatable region above the line of attachment to hinge downwardly over the roof rail region upon encountering resistance by the roof of the vehicle.
In accordance with another potentially preferred aspect of the present invention, the air bag cushion may include regions of restricted inflation extending in a pattern corresponding to the pattern of the roof rail so as to further promote the hinging action of the inflatable region above the roof rail as inflation takes place.
Advantageously, the air bag cushion of the present invention permits the cushioning coverage over the zone of attachment of the curtain-like structure as well as in the region below such line of attachment using a single cushion structure which may be inflated by a single gas generating inflator. The present invention thus provides a useful advantage over prior curtain-like air bag structures which did not provide enhanced cushioning coverage over the roof rail portion of the vehicle.